Bayonet lamp sockets have been known heretofore. A bayonet connection is defined as a device in which the two parts are retained in coupled relationship by pins or projections which extend radially of the coupling engaging axis, the pins being received behind a circumferentially extending abutment in the mating socket part, the engaging motion being first along the coupling axis and then a partial turning about the coupling axis. In bayonet lamp sockets of this type, it has been necessary to manually grip the bulb, locate the slot, push it down into the socket and then turn it a partial turn and release it so that the radial pins engage behind the abutments within the socket and are held therein by a bias spring within the bottom of the socket. Push-push mechanisms have also been known heretofore. For example, E. T. Piber U.S. Pat. No. 3,437,775, dated April 8, 1969, shows a pushbutton switch having a push-push latching mechanism that includes three radial lugs or pins on a movable member and a stationary cylindrical latching liner within the switch that latch the pushbutton down on the first push and release it on the second push. As the pushbutton is depressed, the central portion that carries the radial lugs is forced downwardly until the lugs engage respective cam surfaces on the liner, causing the lug carrying member to rotate. When the pushbutton is released, a bias spring moves the central portion and the lugs carried thereby axially into a catch to latch the pushbutton in the depressed position. When the pushbutton is depressed a second time, the three lugs move downwardly to engage a second set of cams or ridges, respectively, to cause the lug carrying member to rotate further into its release position. When the pushbutton is then released, the bias spring restores the pushbutton axially to its undepressed position.
While the aforementioned bayonet lamp socket has been useful for its intended purpose, it has nevertheless been handicapped by the fact that it has not been generally applicable to a small lamp bulb or the like which cannot be securely gripped by the fingers in its insertion and rotation when mounting the same in a socket. Also, such bayonet lamp sockets have not been generally applicable to structures wherein the lamp bulb, upon being mounted, enters substantially entirely within the shroud or upper walls of the socket because the fingers cannot enter therein to grip the bulb for rotation and removal. Moreover, such bayonet socket lamp bulbs have also been subject to overforce in manual rotation, causing the glass portion of the lamp bulb to break or become loosened from its base thereby damaging the same.